PDA

View Full Version : Simplifying -2^4 x 2 + (-2)^4



LaZy1
07-08-2006, 05:10 PM
I'm given the equation -2^4 x 2 + (-2)^4 I work the equation and I keep getting a 48 but the answer, I'm told, is supposed to be -16. Is there a rule or a little tidbit I've forgotten?

I finished and haven't done anything involving algebra for about 2 years now and I've graduated since then, so I'm a bit rusty and forget little things. Thanks for anyone that helps me with this.

pka
07-08-2006, 05:25 PM
\L
\begin{array}{l}
- 2^4 \times 2 = - 32 \\
\left( { - 2} \right)^2 = 16 \\
\end{array}

TchrWill
07-09-2006, 11:00 AM
I'm given the equation -2^4 x 2 + (-2)^4 I work the equation and I keep getting a 48 but the answer, I'm told, is supposed to be -16. Is there a rule or a little tidbit I've forgotten?

I finished and haven't done anything involving algebra for about 2 years now and I've graduated since then, so I'm a bit rusty and forget little things. Thanks for anyone that helps me with this.
(-2)x(-2) = + 4
(+4)x(-2) = -8
(-8)x(-2) = +16
Therefore,, (-2)^4 = +16
16x2 = 32
32 + 16 = 48

I agree with you.

stapel
07-09-2006, 11:12 AM
I agree with you.
Note the parentheses: -2<sup>4</sup> = -(2)(2)(2)(2) = -16 is quite different from (-2)<sup>4</sup> = (-2)(-2)(-2)(-2) = +16.

Eliz.

TchrWill
07-09-2006, 12:38 PM
Note the parentheses: -2<sup>4</sup> = -(2)(2)(2)(2) = -16 is quite different from (-2)<sup>4</sup> = (-2)(-2)(-2)(-2) = +16.
So right you are. Thanks for making me aware of my misdirection.